Vehicle timed automatic traffic signal



Sept. 24, 1935. w NE|LL 7 2,015,435

VEHICLE TIMED AUTOMATIC TRAFFIC SIGNAL Filed June 13, 1930 2Sheets-Sheet 1 96 J as r\ l 1 1 S 1 as 50 X6 5/ WNZ. B M' W ATTORNEYSept.

C. W. NEILL VEHICLE TIMED AUTOMATIC TRAFFIC SIGNAL Filed June 13, 1930 2Sheets-Sheet 2 1 a wsnwmsQvo. 2 flkkghmg Rmher QvossRed Grossd a \YmumsRefi 4- \ghumaied (muss Go Qmss Amber NVENTOR ATTORNEY5.

Patented Sept. 24, 1935 PATENT OFFICE VEHICLE TIMED AUTOMATIC TRAFFICSIGNAL Charles W. Neill, Syracuse, N. Y., assignor to Grouse-HindsCompany, Syracuse, N. Y., a corporation of New York Application June 13,1930, Serial No. 461,010

7 Claims.

changes the signal indications on the respective streets in an arbitrarymanner regardless of the actual number of vehicles using theintersecting streets. Improvements'over this old style of arbitrarytimer have recently been made, a notable example of which is thenormally go traffic signal which indicates go to traflic on a mainhighway at all times except when a vehicle approaches on theintersecting cross street. Vehicle actuated means located in the trafilclane on the cross street operate the trafiic signal to shift the gosignal, which is normally displayed to the highway, to the cross streetfor a predetermined length of time sufiicient to permit the vehicleapproaching the intersection from the cross street to clear theintersection, after which the normal go signal on the highway isrestored. While this type of signal is a great improvement over the oldstyle arbitrary timer, it is open to certain objections. The go signalfor the cross street is displayed for a predetermined length of timewhich must be sufiiciently long to permit the slowest moving vehicle toclear the intersection during this go period. With fast moving trafficthe go period on the cross street will persist for a much greater lengthof time than is actually needed by the cross street trafiic. Thustrafiic on the main highway is held up unnecessarily.

The principal object of this invention is to provide a traffic signal ofthe vehicle actuated type which will display a go signal to approachingtraffic on a cross street for a period of time which is dependent on thespeed of the traflic. Thus a long period will be provided for slowmoving traffic and a short period for fast moving traffic.Unnecessary'delay of highway traffic is thereby avoided.

A further object of the invention is to provide a trafiic signal whichhas improved time extension means for extending the go period for across street in proportion to the numberof vehicles approaching on thecross street.

A further object of the invention is to provide a traffic signal of thevehicle actuated type in which the go period for a cross street will bedependent on the speed of the cross street traffic, the traffic signalalso having means for displaying a go signal indication to highwaytraffic for a predetermined minimum period of time.

A further object of the invention is to provide a traflicv signal of thevehicle actuated type which has improved means for remembering crossstreet traffic which actuates the vehicle actuated means just after theend of a cross street go period or during a minimum highway go period.

A further object of the invention is to provide improved switching meansfor changing the signal indications with the conventional amber periodfollowing the go signal indication without the use of cam timing means.

A further object and advantage is to provide vehicle actuated meanswhich will be responsive to vehicles approaching from one direction butwhich will not start the traific signal operating mechanism after avehicle strikes a portion of the vehicle actuated means in sweeping awide turn at the intersection.

Other objects and advantages of the invention will become apparent andwill be pointed out as the description proceeds.

The invention consists in the novel features and 20 in the combinationsand constructions hereinafter set forth and claimed.

In describing this invention reference is had to the accompanyingdrawings in which like characters designate corresponding parts in all 2the armatures for controlling the signal circuits during the varioussignal periods.

Location of vehicle actuated detectors A traffic signal S is located inany convenient position so as to be visible to vehicles approaching onthe intersecting streets. As shown in Figure 1 the signal S is of thetype which is located in the center of the intersection. Two vehicleactuated means or detectors D, D are located in the cross street on bothsides of the intersection. These detectors are placed in the lane of theapproaching trafiic which will ordinarily be to the right of the centerline of the street. The detectors D and D may be set in any spacedrelation relative to one another. It is preferable, however, for thefirst detector D to be set back a sufiicient distance from theintersection so that the signal will have time to change before thevehicle reaches the intersection thus permitting the vehicle to crossthe intersection without stopping or slowing down. Since it isconventional practice to display an amber signal to the highway beforechanging the signal indication to stop, the detector D should be setback from the intersection sufficient distance to permit the highwayamber period to elapse before the vehicle on the cross street reachesthe intersection. The detector D operates the signal operating mechanismto change the signals so as to display a go signal to the cross streetand stop signal to the highway, this stop signal may be preceded by theconventional amber.

The detector D starts the operating mechanism to restore the normalhighway go signal and cross street stop signal. It is desirable that thedetector D be so located in the cross street that any traffic on thecross street, which is waiting for a change in the signal, will stopover the detector D or before reaching the d tector D but will not crossthe detector D before stopping. Local conditions may determine theposition and relation of the detectors D' and D with respect to theintersection and to each other.

Any suitable vehicle actuated means may be used as the detector D or DVehicle actuated means such as a depressible treadle similar to thatshown in the patent to Nelson No. 1,665,560 issued April 10, 1928, maybe used. However, in connection with the apparatus here disclosed, thecontacts of the treadle are normally closed, and are opened by a vehiclepassing over the treadle.

Effect of operation of the first detector The vehicle actuated means arearranged so as to break the circuit to magnetic relays I6 and H. When avehicle actuates the detector D the relay Ill will be de-energized andpermit the armature l2 to drop. When the detector D' is no longer underthe influence of the vehicle the armature 12 will again be drawn up bythe relay [0, into the position shown in Figure 2.

When a vehicle actuates the detector D the relay l I will bede-energized and will permit the armature l3 to drop. When the detectorD is no longer under the influence of the vehicle, the armature l3 willagain be drawn up into its raised position by the relay II. I

As a vehicle approaches the intersection on the cross street, it willactuate the detector D to cause the relay It to permit the armature 22to drop on the contacts l5 and [6. The contact [5 is hot at all timesand when the armature :2 drops on these contacts l5 and I 6, power willflow through the armature I2 and the resistance l1, stick relay I8, andresistance l9, to the ground.

The stick relay i8 will be energized to throw its armature 20 intoengagement with the contact 2|. This establishes a new circuit from thecontact 15 through the armature 12, contact it, stick relay 22, armature20, contact 2|, stick relay l8, and resistance 19 to the ground. Thestick relay 22 will attract its armature 25 into engagement with thecontact 26. This establishes a new circuit from the armature l3, whichis hot at all times, through the contact 30, armature 25, contact 25,stick relay 22, armature 25!, contact 2|. stick relay l8, and resistancel9, to

the ground. This last described circuit will stick the relays 22 and i8,and the breaking of the circuit at contact l5 when the armature l2 risesafter the vehicle on the cross street passes the detector D will have noeffect on the relays.

A conductor 35 connected to the circuit between the stick relay [8 andresistance I9, leads to a coil 35 of a motor 31. The motor may be of anyconventional type suitable to operate the switching mechanism, and whichis provided with forward and reverse coils. The motor here shown is ofthe induction disk type provided with the coils 36, 89, to rotate thedisk in opposite directions. When the operating mechanism is in normalposition, as shown in Figure 2, the coil 36 is grounded through a stickrelay 38 and brush 39, which contacts with a grounded conductor segmentas of the commutator 4|.

The purpose of the resistance ll is to obtain a voltage drop across thestick relay 22 and the purpose of the resistance i9 is to obtain avoltage drop across the motor coil 36.

When power is supplied to the motor coil 36 the motor 3': will operatein a forward direction, clockwise, as shown in Figure 2, and turn theshaft 42 on which the commutator 4| is mounted.

As the commutator 4i turns in a forward or clockwise direction thegrounded conductor segment 4!! will move into contact with a brush 45which connects with an armature 46 of the stick relay 38. The brushes 39and 45 are so spaced with relation to one another that the groundedconductor segment 48 will contact with the brush 45 before it breaks itscontact with the brush 39. When the brush .5 makes contact with thegrounded conductor segment 49 a new circuit will be established from thestick relay 38 through a contact 48, armature 4t, and brush 45 to thegrounded conductor segment 49. This circuit will stick the relay 36after the contact between the brush 39 and grounded conductor segment 63is broken.

Operation during forward rotation The signal lights are c erated bysuitable switching means, here shown as relay operated switches. Theoperation of the signals by these switches will be described later. Theswitches are operated by relays 5S and 5E which connect with suitablecrushes on the commutator The relay 5! is connected by a conductor witha contact 53. When the relay 38 is operated to attract the armature 45contact is established between the contacts 53 and armature 65. Thearmature 45 is of the double type being made up of two conductorsections insulated from one another. That part of the alt nature 45which engages with the contact 48 connects with the brush 45. The partof the armature 45 which engages with the contact 53 connects with abrush 4 5 As the commutator 4! turns in a forward or clockwisedirection, the grounded conductor segment do will come into contact withthe brush 45 A new circuit is thus established through the relay 53, oneside of which is connected with a suitable source of current, conductor52, contact 53, armature 46, and brush 45 to the grounded conductorsegment ie. The flow of current through the relay to will cause thearmature 55 to be drawn to the left in Figure 2, to change the si nalindications so as to display the highway amber; the cross red remainingunchanged.

As the commutator 4| turns in a forward direction, a hot conductorsegment 69 will come in contact with a brush 6| which connects with therelay 5|. The other side of the relay 5| is connected with a contact 62,but during the forward movement of the commutator 4 I the armature 46 isout of engagement with the contact .BZ and there is therefore nocomplete circuit through the relay 5|.

As the commutator 4| continues to: rotate in a forward direction thegrounded conductor segment 40 will come into contact with a brush 65.This provides an additional ground connection for the relay 5|], but isof no importance during the forward rotation of the commutator 4 I.

When the commutator 4| has rotated in a forward direction until theinsulated segment El comes under the brush 45, the ground connection ofthe relay 38 will be broken and the armature spring 68 into engagementwith the contact 62,

a circuit is established from the hot conductor segment 68 through thebrush 6|, relay 5|, contact 62, armature 4B, and brush 45,'to thegrounded conductor segment 48, the end of which is now located betweenthe brushes 45 and 45 When this circuit is established through the relay5| the armature I'll will be moved to the left in Figure 2 to change thesignal indications to display the highway red and cross street gosignals.

The operating mechanism will now remain in this position until a vehicleactuates the detector D Efiect of operation of the second detector Whena vehicle actuates the second detector D the relay II will permit thearmature iii to drop out of engagement with the contact 3% and intoengagement with a contact 12.

The breaking of the circuit between the armature l3 and the contact 38will cut ofi the supply of power to the armature 25 and stick relay 22.This will cause the stick relay 22 to break, a spring 13 being providedto withdraw the armature 25 from the contact 26 when the relay 22becomes deenergized.

The source of power to the stick relay l8, through the stick relay 22 isbroken, but a new circuit is established from the armature 53 throughthe contact 72, and armature 28 to the contact 2| and stick relay I8.The break in the current while the armature l3 moves from the contact 30to the contact 12 is of such short duration that the stick relay l8 willnot break.

When a vehicle has passed the'second detector D the relay II will againattract the armature l3 and the contact between the armature l3 andcontact 72 will be broken. This will break the circuit, just described,to the stick relay l8 and a spring 15 will draw the armature 20 to theleft in Figure 2, out of engagement with the contact 2| and intoengagement with contacts 16 and Ti. The contact 16 is hot at all timesand a new circuit is established fromthe contact 16 through the armature29, contact 11, conductor 18, motor coil 80, conductor 8|, contact 62,armature 46, and, brush 4%, to the grounded conductor segment 40. Theflow of current through the motor coil 30 will cause the motor to rotatein a reverse direction so as to turn the commutator 4| in acounterclockwise or reverse dire tion.

Operation during reverse movement of the motor As the commutator 4|rotates in a counterclockwise or reverse direction the groundedconductor segment 48 will'move into contact with 1 the brush 45, butduring reverse movement the armature 46 will occupy the position shownin Figure 2 and no circuits are connected with that portion of thearmature 46 which connects with the brush 45. 15

The commutator 44 will continue to rotate in a reverse direction andbring the insulated segment 85 under the brush 65. This will break thecircuit through the relay 5! and the armature 55' will be drawn to theright in Figure 2, by a 20 spring 86. This movement of the armature 55will cause a change in the signals so that the cross amber signal isdisplayed, the highway red signal remaining unchanged. The position ofthe brush 65 is adjustable so as to determine how 25' long the crossstreet go signal will persist afterthe commutator 4| begins its reverserotation.

A brush 95!, which is also adjustable, is set so that the hot conductorsegment 60 will contact with this brush 90 at the same time that theposition, shown in Figure 2, the insulated segment 61 will come underthe brush 5| and cut off the supply of power to the relay 5 I. Thearmature 1|] will then be drawn to the right by a spring 88. Thismovement of the armature it will restore the signals to their originalcondition displaying the highway go and cross street red signals. Theinsulated segment 85 will come under the brush 45? thus breaking theground connection of the motor coil 88 and the motor 31 will stop, thecommutator 4| coasting slightly until it reaches the position shown inFigure 2.

Minimum highway go period The operating mechanism illustrated in Figure2 provides a minimum highway go period.

When the insulated segment 85 comes under the brush 65,during reverserotation of the com- :mutator 4|, the relay 59 is deenergized and thearmature 55 moves to the right to change the cross street signal toamber as previously described. v The commutator 4| continues its reverserotation until the insulated segment 61 comes under jthe'brush 6|. Thesignals are then changed to their normal position of highway go andcross street red, but the time of this change may be adjusted bychanging the position of the brush 6|. The time required after theinsulated segment 6'| has come under the brush 6| for the commutator 4|to complete its reverse rotation and move through the first part of afollowing forward rotation, provides a minimum period for the go signalon the highway.

The time between the contact of the insulated I segment with the brush65 and the contact of the This is to prevent time ex- 35:

insulated segment 61 with the brush 6| will be the cross street amberperiod and these brushes 65 and El should be so adjusted with respect toone another that a cross street amber period of prope duration isobtained.

The motor coil may be so wound, or so placed with respect to the motor31, that the reverse rotation of the motor 31 is at a slower rate thanwas the forward rotation. This is highly desirable in connection withthe setting of the brushes of the operating mechanism so as to obtainthe desired minimum highway go period. The maximum highway go periodwill depend entirely upon the density of the cross street trafiic sincethe go signal is normally displayed to the highway at all times unless avehicle crosses the vehicle actuated means in the cross street.

Time extension feature The apparatus is designed so as to start areverse rotation of the operating motor to restore the signals to theirnormal position within a very short time after a vehicle passes thesecond detector D The length of time, after a vehicle passes thedetector D before the cross street go signal changes to amber isadjustable by changing the position of the brush 65 as above described.This time will depend on the width of the intersection and should bejust sufficient so that when added to the cross street amber period avehicle will be permitted to clear, or almost clear, the intersectionbefore the display of the highway go signal.

In order to obtain efiicient handling of the traflic, it is necessarythat means be provided by which the go period for the cross street canbe extended in order to permit a group of vehicles to cross during thesame period. The time extension is provided by the operating mechanismshown in Figure 2.

If a vehicle crosses the detector D at any time during the cross streetgo period and after the vehicle ahead of it has actuated the seconddetector to start reverse movement of the motor, the stick relays 22 andI8 will be operated in exactly the same manner as previously describedin connection with the first vehicle to cross the detector D. No currentwill flow through the conductor 35, however, because the groundconnections of the conductor 35 are broken; the brush 39 is incontactwith the insulated segment 61, and the armature 46 is not in engagementwith the contact 48. When the relay I8 is energized by this secondvehicle passing across detector D, the armature 20 is drawn to the rightand the circuit from the contact 15 to the motor coil 80 is broken thusstopping the motor. The motor will remain stopped and the signals willremain in position displaying a go signal to the cross street until thesecond vehicle has passed over the detector D Reverse rotation of themotor will then be resumed, the mechanism operating as in the case ofthe first vehicle to cross the detector D If the second vehicle does notreach the detector D, until after the cross street go signal has changedto amber, no time extension of the amber period will result. The stickrelays 22 and I 8 will be operated but they will not stop the reverserotation of the motor. Power to continue the reverse rotation of themotor will be supplied from the hot conductor segment 60 which comesinto contact with the brush to supply power to the motor coil 80, whenthe cross street signal changes to amber.

Memory feature When a second vehicle on the cross street reaches thedetector D during the cross street amber period, or during the crossstreet stop period, but before the operating mechanism has completed itsreverse rotation, means are provided by which the mechanism rememberssuch second vehicle.

This second vehicle will stick the relays 22 and I8 as previouslydescribed. When the commutator 4| has moved in a reverse direction untilthe ground conductor segment 40 contacts with the brush 39, a circuitwill be completed from the stick relay 8 through the conductor 35, motorcoil 36, relay 38, and brush 39 to the grounded conductor segment 40.The armature 46 will be drawn to the left, thus breaking the groundconnection of the motor reverse coil 80. The motor will thus drive theoperating mechanism forward to give a cross street go signal to thewaiting vehicles.

Signal switching means The operation of the signal lights by theswitching means is illustrated in Figure 3. The relay 55, whenenergized, draws the armature 55 to the left to engage the contact point95. When the relay 50 is not energized the armature 55 is When neitherof the relays 50 or 5| is energized 40 and both armatures 55 and 10 arein their normal position, as shown in Figure 3, the signals will be intheir normal position displaying highway go signal and cross street redsignal. The circuit will be readily understood by reference to Figure 3,and may be traced from the armature 10 through the contact 98, highwaygo signal, contact 96, and armature 55 to the ground. The cross streetred signal is in a parallel circuit which may be traced from thearmature 10 through the contact 98, and cross street red signal to theground.

When the relay 50 alone is energized, the armature 55 is drawn intoengagement with the contact thus breaking the circuit through thehighway go signal and establishing a circuit from the armature 16through the contact 98, highway amber signal, contact 95, and armature55, to the ground.

When both the relays 50 and 5| are energized, a circuit is establishedfrom the armature 15 through the contact 91, and highway red signal, tothe ground. A parallel circuit is established from the armature 10,through the contact 91, cross street go signal, contact 95, and armature55, to the ground.

When the relay 5| only is energized the circuit through the highway redsignal remains, but the parallel circuit is now from the armature 10,through the contact 91, cross street amber signal, contact 96, andarmature 55, to the ground.

While I have illustrated my invention in a preferred embodiment, variouschanges and modifications may be made therein without departing from thespirit of the invention as set forth in the appended claims.

What I claim is: l

1. A traffic signal for directing traffic at the intersection of twohighways, including signals normally indicating go to one highway andstop to the other, and means for shifting and reshifting said signalindications to the respective highways,

said shifting mechanism including first and second vehicle actuatedmeans located in one of said highways, and arranged to be successivelyactuated by traffic approaching the intersection on said highway, signalswitching mechanism operable, upon actuation of the first vehicleactuated means, to move in one direction from initial position toreverse said signal indications and operable, upon actuation of thesecond vehicle actuated means, to move in reverse direction to reshiftsaid signal indications back to normal and maintain said indications inreshifted position a predetermined minimum length of time before saidsignals can again be shifted from original position.

2. A traflic signal for directing traffic at the intersection of ahighway and a cross street including a signal device having signalsnormally indicating go to the highway and stop to the cross street, andhaving a caution signal to indicate signal changes, means for shiftingand reshifting said go-stop signals and operating said caution signal,including a first and second vehicle actuated means located in spacedapart relationship in the cross street, and arranged to be successivelyactuated by trafiic approaching the intersection on said cross street,switching mechanism operable, upon actuation of the first vehicleactuated means, to shift said highway go signal to caution and after apredetermined time to shift the cross street stop signal to go, and thehighway caution signal to stop, and operable, upon actuation of thesecond vehicle actuated means, to shift the cross street gosignal tocaution and subsequently the highway stop signal to go and the crossstreet caution to stop, and maintain the signals in said reshiftedposition a predetermined minimum period of time before they can again beshifted by actuation of the first vehicle actuated means.

3. A traffic signal for directing traffic at the intersection of ahighway and a cross street including a signal device having signalsnormally indicating go to the highway and stop to the cross street, andhaving a caution signal to indicate signal changes, means for shiftingand reshifting said go-stop signals, and operating said caution signal,including a first and second vehicle actuated means located in spacedapart relationship in the cross street, and arranged to be successivelyactuated by traffic approaching the intersection on said cross street,switching mechanism operable, upon actuation of the first vehicleactuated means to shift said highway go signal to caution, andsubsequently shift said caution signal to stop on the highway and go onthe cross street, and said switching mechanism being operable, uponactuation of the second vehicle actuated means, to reshift the crossstreet go signal to stop and the highway stop signal to go, and causesaid highway go signal to persist a predetermined minimum length of timebefore said sig nals can again be shifted.

4. A highway traffic signaling device for intersecting highwaysincluding signals normally indicating go to one highway, and stop to theother, mechanism for shifting and reshifting said signals to reverse andto restore the indications to the respective highways, said shiftingmechanism including first and second vehicle actuated means located inone of said highways in spaced apart relationship, and arranged to besuccessively actuated by traffic approaching the intersection on 5signals can again be shifted by actuation of the 15 first vehicleactuated means. I

5. In a highway traffic signaling device for intersecting highwaysincluding signals normally indicating go to one highway, and stop to theother, means for shifting and reshifting said sig- 20 nals to reverseand restore the signal indications to the respective highways, saidshifting means including a first and a second detector located in one ofsaid highways in spaced apart relationship, and arranged to besuccessively actuated by 25 traffic approaching the intersection on saidhighway, and switching means operable, upon actuation of the firstvehicle actuated means, to shift said signal indications from go to stopon one highway, and stop to go on the other highway, 30 and operable,upon actuation of the second Vehicle actuated means, to reshift saidsignal indications to their-initial display, and operable, upon asubsequent actuation of the first vehicle actuated means during thereshifting of the signals, 5

cluding signals normally indicating go to the 4 1 highway and stop tothe cross street, and also including a caution signal to indicate signalchanges, means for shifting and re-shifting said go-stop signals, andoperating said caution signal, including first and second vehicleactuated means 50 located in spaced apart relationship in the crossstreet, and arranged to be successively actuated by traflic approachingthe intersection on said cross street, said shifting and re-shiftingmeans also including switching mechanism operable, upon actuation of thefirst vehicle actuated means, to shift said highway go signal tocaution, and subsequently shift said caution signal to stop, and shiftthe stop signal on the cross street to go, and said switching mechanismbeing further operable upon actuation of the second vehicle actuatedmeans to reshift the cross street go signal to caution, and subsequentlyshift said caution signal to stop on the cross street, and said stopsignal to go on the highway, and cause said signals to 5 display go tothe highway and stop to the cross street for a predetermined minimumtime before said signals can again be shifted, and said shiftingmechanism being further operable upon actuation of the first vehicleactuated means during the display of the go signal on the cross streetto arrest said reshifting until subsequent actuation of the secondvehicle actuated means.

7. A traflic signal for directing traffic at the intersection of ahighway and a cross street including signals normally indicating go tothe highway and stop to the cross street, and also including a cautionsignal to indicate signal changes, means for shifting and re-shiftingsaid go-stop signals, and operating said caution signal, including firstand second vehicle actuated means located in spaced apart relationshipin the cross street, and arranged to be successively actuated by traflicapproaching the intersection on said cross street, said shifting andre-shifting means also including switching mechanism operable,

upon actuation of the first vehicle actuated means, to shift saidhighway go signal to caution, and subsequently shift said caution signalto stop, and shift the stop signal on the cross street to go, and saidswitching mechanism being further opation of ,the first vehicle actuatedmeans during 10 the display of the cross street caution signal, or thehighway go signal, to cause said signals to again be shifted from theirnormal indication to stop on the highway and go on the cross street.

CHARLES W. NEILL.

